Alkylation process



Aug. 4, 1959 J. T. KELLY ET AL ALKYLATION PROCESSV Filed Jan. 8, r1958United States Patent O ALKYLATION PROCESS Joe T. Kelly, Dickinson, andHarmon M. Knight, La

Marque, Tex., assignors to The American 'Oil Conlpany, Texas City, Tex.,a corporation of Texas Application January 8, 1958, Serial No. 707,735

1`1 Claims. (Cl. 26th-683.44)

This is a continuation-impart of our copending applications 605,052 and605,053 filed August 20, 1956 and now abandoned.

This invention relates to the reaction of isoparaliins or aromatichydrocarbons and olelins. More particularly it relates to the alkylationof isobutane with ethylene.

In the petroleum industry today, the octane race has placed a strain onfacilities and materials needed to make gasoline meeting present dayautomotive engine requirements. One of the remaining sources of highoctane components is the product of the alkylation of isobutane andethylene. This alkylation is not easy to carry out, particularly on alarge scale. l

An object of the invention is the 'alkylation of isoparaiiins,particularly isobutane, with oleiins, particularly v ethylene. Anotherobject is the alkylation of aromatic hydrocarbons with olelins. Otherobjects Will become Aapparent in the course of the detailed description.

The alkylation of isoparafns or aromatic hydrocarbons with olens iscarried out in the presence of a novel catalyst pair. One member of thecatalyst pair is boron 'trifluoride The other member of the catalystpair is an alkyl acid phosphate ester, that is, an alkyl hydrogenphosphate. Although the second component of the catalyst pair is spokenof as an alkyl acid phosphate, it is believed that the second member ismore properlyra complex of the hereinafter defined ester and BF3 con'-taining about l to 2 moles of BF3 per mole of ester, depending upon thenumber of free acid groups present in the ester.

Boron trifluoride is one member ofthe catalyst pair. Commercial gradeanhydrous boron trifluoride is suitable vfor use as one member of thecatalyst pair. Y

The other member of the catalyst pair, hereinafter spoken of as theester member, is an alkyl acid phosphate, i.e., an alkyl hydrogenphosphate ester.

The ester may be derived from any one of the various forms of phosphoricacid, for example, pyrophosphoric acid, orthophosphoric acid orapolyphosphon'c acid. The ester may be used as the liquid or it may besu'pported on a solid carrier such as charcoal, silica gel, alumina,slag, etc. The ester may be essentially anhydrous or may contain smallamounts of Water, on the order of 5% or less. The alkyl group present inthe ester may contain from 1 to about 13 carbon atoms. The ester maycontain either 1 or '2 alkyl groups, i.e., at least l hydrogen atom mustbe present.

The BF, Vand the defined ester react to form 'afviscous materialcontaining complexed BF3. When the ester and BF3 are contacted in aclosed vessel, the 4BFS partial pressure drops very rapidly at irst andthen 'gradually approaches a constant value. It appears that a veryrapid reaction between the BF3 and ester takes place.

A complex of the defined ester and BF3 is not as effective for thealkylation in vthe absence of free-EP3. Free-EP3 is to be understood asBF3 existing in the 'reaction zone which is not complexed with thedefined ester. As soon as the ester has complexedV with some BF3, thebeneficial catalytic eiect exists. Thus free-BFS may exist in thereaction zone, as evidenced by the formation of alkylate, even thoughall of the ester has ri ICC not been complexed. In a batch system,wherein less EP3 is present than is theoretically required to complexall the ester present, eventually little further alkylation Will occuras charge is added, since all of the BF3 will have been complexed.

In general, the process is carried out utilizing an amount of BF3 whichis in excess of that required to complex with all the ester present inthe contacting zone, namely, in excess of about 1 mole of BFS per acidequivalent of ester present. More than the minimum amount of free-EP3 isbeneficial, in fact, the yield of alkylate increases rapidly withincrease in free-BFS present, up to a maximum amount. The amount offree-BE, used Vis dependent somewhat upon the reactants themselves.`However, when reacting isoparalins and oleins, the free-BF3 usage isdesirably, set out on a BF3 to olefin weight ratio, of at least about0.2. In other words, at least about 0.2 lb. of free-EP3 per lb. ofolefin charged to the alkylation zone is desirable. About 1.5 parts byweight of BFS per part of olelin charged appears to be about thedesirable maximum usage of BF3. It is preferred to use between about0.35 and 1 part by Weight 'of free-EP3 per part by weight of olen whenutilizing `the lower molecular Weight olen, such as ethylene andpropylene.

The process may be carried out at any temperature l-below thetemperature at which the ester-BE, complex, 'as well as the esteritself, decomposes. The temperature -bf operation may be as low as 20 C.or even lower. Temperatures as high as 125 C. and even higher may vbeused with some of the esters which have relatively high decompositiontemperatures. Low temperatures appear to favor the formation of thehydrocarbons having '6 carbon atoms.

Suici'ent pressure is maintained on the system y'to keep 'a Substantialportion of the hydrocarbons charged in the liquid state.- The processmay be carried out at relatively low pressures, for example 100 p.s.i.,or it may be carried out at elevated pressures, for example 2000 p.s.i.,or more. Ingeneral, pressures will be between about 200 and 1000 p.s.i.and preferably between about 300 and i600 p.s.'i.

The contacting of the 'isoparaliin or aromatic hydrocarbon and theolefin in the presence of the dened cat- -alyst pair is continued untilan appreciable amount of 'alkylate has been formed. In batch reactions,it is pos'- sible to convert substantially 100% of the olen byV asufficiently long period of contacting. When operating' in a continuousiiow system, it may be desirable to have a time of contacting such thatsubstantial amounts of olefin are not .converted and obtain the completecon# version of the olelin vby a recycle operation. The time of reactionwill be determined by the type of hydrocarbons charged, the ratio ofisoparafn or aromatic to olefin, the degree of mixing in the contactingzone and the catalyst usage. A few tests will enable one to determine4the optimum time of contacting for the particular system of operatingconditions being tried.

The reactants in the hydrocarbon charge to the alkylation process areisoparaiiin, or aromatic and olefin.V The olefin contains from 2 toabout l2 carbon atoms. Ex'- amples of suitable olefins are ethylene,propylene, butene- 2, hexene and octene; in addition to these, theolelin poly mers obtained from propylene and/or butylene are alsosuitable for use in the process, such as codimer, propyl ene trimer,propylene tetramer and butylene -trimen It is preferred to operate withethylene or propylene.

The aromatic hydrocarbons must be alkylatable by :the particular olefinused. It is self-evident that .an aromatic hydrocarbon'which containsalkyl substituents `"positioned 'so that steric hinderance would preventor greatlyreduce the possibility of alkylation with the particularolefin 3 should not be subjected to the process. Examples ofparticularly suitable aromatic hydrocarbons are benzene, toluene,xylene, trimethylbenzene, and other alkyl `analogues, such as propyl andbutyl; theV naphthalene aromatic hydrocarbons, such as the mono anddi-substituted methylnaphthalenes Q The isoparafiin reactant is definedas a parafnic hydrocarbon which has a tertiary hydrogen atom, i.e.,paraiiins lwhich have a hydrogen atom attached toV a tertiary carbonatom. Examples of these are isobutane, isopentane ('2-methylbutane),2-methylpentane, 2-methylhexane, 3- methylhexane, 2,3-dimethylbutane(di-isopropyl) and 2,4- `dimethylhexane. Thus the isoparaiiins usable asone reactant in the process contain from 4 to 8 carbon atoms.

In the isoparatiin-oleiin system, the alkylation reaction is morefavored as the mole ratio of isoparal'lin to olefin increases. Ingeneral, lthe isoparaiiin to olen mole ratio in the hydrocarbon chargeshould be at least l. More than this amount is good and it is desirableto have an isoparafin to oleiin ratio between about 2 and 25 and in somecases more, for example, as much as 50.A It is preferred to operate withan isoparaiiin to oleiin mole ratio of between about 5 and 15.

h The presence of non-reactive hydrocarbons in the hydrocarbon charge isnot detrimental unless the reactants become excessively diluted. Forexample, the isoparain may also contain isomers of the normalconfiguration. The oletins may contain parains of the same carbonnumber. Mixtures of 2 or more isoparaiiins or 2 or more aromatichydrocarbons, or 2 or more olefns may be charged. In general, when aparticular product distribution is desired, it is preferable to operatewith a single isoparaiiin and a single olefin, for example,rtechnicalgrade isobutane and ethylene, both of about 95% purity.

The reactants may be mixed together before they are charged into thereactor. Or, they may be charged into the reactor separately. Or, aportion of the olefin may be blended with the isoparaiiin or aromaticbefore introduction into the reactor and the remainder of the olefininjected into the reactor. The charge may be introduced all at one pointinto the reactor or it may be introduced at 2 or more points. Thealkylation reaction is exothermic and temperature control is facilitatedby introducing the olefin into the reactor at more than one point.

The BF3 member of the catalyst pair may be premixed with the isoparainand olefin before introducing these into the reactor but this should notbe done when an extremely reactive system such as isobutanes andisobutylene or aromatic hydrocarbons and olens are being used; or whenan olefin that is very rapidly polymerizable is being used. The EP3 maybe blended with the isoparafn reactant and introduced into the reactorwith this member when the isoparafiin and the oletins are beingintroduced separately. The BF3 may also be introduced directly into thereaction zone independently from the hydrocarbons charged. The BF3 maybe introduced into the reactor at a single point or at several points tohelp control temperature and reaction rate.

The reactor may be a vessel providing for a batch-type reaction, i.e.,one wherein the desired amount of isoparafiin or aromatic and olefin arecharged to a closed vessel containing the catalyst pair and the vesselthen maintained at the desired temperature for the desired time. At theend of this time, the hydrocarbon product lmixture and unreactedmaterials are withdrawn from the vessel and processed to separate thealkylate product from the un.- reacted materials and lower and highermolecular weight materials. The reactor may be a stirred vessel whereinthe reactants and free-BE, are flowed through a liquid pool of theester-BF3 complex, the space velocity being controlled so that thedesired amount of reaction is obtained during the passage of thereactants through the pool. Other methods of operation common in thecatalytic rening aspects of the petroleum industry utilizing viscousliquid catalyst may be readily devised.

It has been pointed out that the ester member of the catalyst pair isreally a complex of the alkyl acid phosv phate and BFS; the BF3apparently reacting with the ester. The complex may be preformed, byexposing the ester to BF,x for a time. sufiicient to introduce some BF3into the ester component or even enough to complex all the ester; thisbeing done before the reactants are introduced. into the reaction zoneor even before the ester member of the, catalyst pair is positioned inthe reaction zone. The complex may be formed in situ during a batchtypereaction. In the batch-type operation, it is convenient to -introduceall the BFa into the reaction vessel at once. This amount of BF3 issufficient not only to complex the ester but also provide the desiredamount of free- BE3. In,` a stirred system, the ester-EP3 member may beprepared in situ by charging fresh ester to the reaction zone andforming the complex during the initial passage of reactants .and BF3through the pool. Some alkylation reaction occurs even though the poolhas not taken up sufficient BF3 to complex all the ester. As the iiow ofreactants and BF3 continues through the pool, eventually the ester willbecome saturated with respect to BF3. At this time, the amount of BF3introduced into the reaction zone should be lcut back to that amount offree-BE, desired, under this particular set of of operating conditions.

The illustrative embodiment set out in the annexed gure forms a part ofthis specification. It is pointed out that this embodiment is schematicin nature, that many items of process equipment have been omitted, sincethese may be readily added by those skilled in this art and that thisembodiment is only one of many which may be devised, and that theinvention is not to be limited -to this particular embodiment.

In the figure, it is desired to produce a high yield of diisopropyl foruse as a blending material for gasoline. Ethylene from source 11 ispassed by way of line 12 into mixer 13. Liquid isobutane from source 14is passed byway of lines 16 and 17 into mixer 13. Both the ethylene andthe isobutane are about purity, the remainder being n-butane and ethane,with trace amounts of other components found in materials derived frompetroleum relining sources. Mixer 13, in this instance, is a simpleorifice-typel mixer suitable for intermingling aliquid and a-gas, or twoliquids. Recycle isobutane from line 18 is passed by way of line 17 intomixer 13. In this embodiment, the molar ratio of isobutane to ethyleneis 6.v Y

. From mixer 13, the blend of isobutane and ethylene is passed by way ofline 19, through heat exchanger 21, where the temperature of the blendis adjusted to 30 C. The temperature of the blend leaving exchanger 21,the stream'of isobutane and ethylene is passed by way of lines 22 and23into Athe bottom of reactor 24. Boron triiiuorirde is passed from source26 by way of valved line 27 and line 28 into line 23, where it meets thestreamv of isobutane and ethylene. If desirable, a mixer may beintroduced into line 23 to insure complete intermingling of the BF3 andthe hydrocarbon charge; Recycle BF3 is introducedfrom line 29 by way oflines 28 and 23. In this embodiment, the ester is completely complexedwith respectA to BF3 and only the necessary free-BF3 is introduced byway of line 28. The weight ratio of free-BE, from line`28 to ethylenepresent in line 23 is 1:1.

Reactor 24 is shown as a vertical cylindrical vessel containing turbinestirrers 25 driven by motor 36. In order to maintain the temperature inthe reactor at substantially 10 C., other cooling means may beintroduced through the pool of liquid in reactor 24 by means not shown.

In this embodiment, Vthe reactor was charged .with diethyl hydrogenorthophosphate containing about.l% of water. The ester was contactedwith' BFa in an amount such that all ,of the ester was complexed with w.I.- d

BF3. This operation was carried out before reactants were introducedinto the reactor. The reactor pressure was maintained at 600 p.s.i. Thispermits maintaining the isobutane and substantially all of the ethylenein the 6 5 9 andis adapted to produce the desired alkylate productsYfrom the hydrocarbon' product mixture entering from line S6. 'A vaporstream is taken overhead by way of line 61, is condensed in cooler 62and is passed to storage liquid state. 5 byrwaiy 4of line 63. Thematerial from line 63 consists The product hydrocarbon mixture, complex,and substzlmtally ot` isopentane and some unsaturated C5 free-EP3 ispassed out of reactor 24 by way of line 31. material. This material maybe used as a high octane T'he stream from line 31 is passed intocatalyst sepablending stock for the production of motor gasoline ofrat'or 32 where the BF3, isobutane, pentanes and alkylate the desiredvolatility characteristics. product. are separated from the complex andtaken out 10 The alkylate product herein is considered to be that by Wayof line 33. The stream from line 33 is passed boilingl above the pentanerange and boiling below the into gas separator 34 Where the BFS,isobutane, some maximum temperature usable in motor gasoline.v Inpentanesv andsome alkylate product are taken overhead general, a 415 F.endpoint alkylate is blendable into by way of line 35. The materialtaken overhead from motor gasoline without adverse eitect in aspecication gas separator 34 is passed into fractionator 44. 15 callingfor a 400 F. gasoline endpoint. Thus the alkylate Fractionator 44 isadapted to separate the BF3 as a product is considered to be thematerial boiling between gas,` the isobutane as. a liquid and the higherboiling about the lower limit of the hexane range and 415 F. materialsas a bottom product. Fractionator 44 is proin the ASTM distillationprocedure. p v vided with an internal reboiler 46 and an internal con- Aconsiderable difference exists between the octane denser 47. BF3 andunreacted ethylene are taken 20 number of the C6 fractionv of thealkylate product and overhead from fractionator 44 by way` of line 48and the higher boiling material. The C6 fraction, which boils may bepassed out `of the system by Way of valved line from about 110 to 170 F.has an F-l octane number of 49. The material from line 49 may beperiodically 101. The Cq-lmaterial has an octane number which passed toa BF3 purification operation to remove nonranges between about 75 and85, depending somewhat on condensable inert gases Which build up in thesystem. the fractionation. Y i Ordinarily the stream from line 48 isrecycled by way Light alkylate, which includes all the C6 material andof valved lines 29 and lines 28 and 23 to reactor 24. some of the C,material, is withdrawn from fractionator vIsobutane is withdrawn as aliquid stream by Way of 57 by Way of line 66. Heavy alkylate, whichincludes line 51 and is recycled by way of lines 18 and 17 to most oftheC7 and materialV boiled upto 415 F. is withmixer 13 for reuse in theprocess. Bottoms product 30 drawn from fractionator 57 by Way of line67. A small from fractionator 44 is withdrawn by way of line 52 amountof higher boiling bottoms is withdrawn by way and may `be passed tostorage or further processing by of line 68. Way of valved line 53.This. stream from line, 52. con- The heavy ester-BF3 complex carriedover into catalyst sists substantially of isopentane. Some unsaturatedC5 i separator 32 is removed by way of line 69 and returned hydrocarbonsare also present and also` a small amount to the bottom of reactor 24.Make-up ester may be inof higher boiling alkylate material. A Y itroduced by way of valved line 71 and line 69.

The liquid hydrocarbons from gas separator 34 are The results obtainableby the process of the instant inpassed by way of line 54 into washingoperation 55, vention are set out in illustrative runs below. whereoccluded ester is removed; for example, by caustic In lTable I, thereare set out results in the testing of treatment. The Washed material ispassed by way of various alkyl acid orthophosphates by means of batchline 56 into fractionator 57. The lbottoms product from operation. Inthese runs, the tests were carried out under fractionator 44 may bepassed by way of valved line 58 what, are more or less standardconditions, namely, a 4- and line 56 into fractionator 57 for completeremoval of liter-carbon steel bomb Was dried overnight in a stream ofthe alkylate material. In this embodiment, the bottoms hot air at 110 C.The ester to be tested (90 grams) was are passed to fractionator 57.charged to the bomb as a liquid and the bomb was evacu- Fractionator 57is provided with an` internal reboiler ated. One kilogram of a dry blendof ethylene and iso- -Table l Run No 1 2 s 4 5i Ester d.... DiethylEthyl Dlisoctyl Isooctyl Ethyl Hydrogen dhydrogen hydrogen dihydrogendihydrogen Ortho- Ortho- Ortho- Ort o- Ort ophosphate phosphatephosphate phosphate phosphate Conditions:

Isobntane/Olen (Molar) 2. 8 2. 8 2.8 2. 8 2. 8 Hydrocarbon/Ester(Weight) 11. 0 11. 2 11.2 11.1 5. 6 BFa/Ethylene (Wei 0.7 0.8 0.7 0.80.5 v'rime V 20 2o 20 20 20 Temperature C 20-25 20-25 20-25 20-26 30-35Pressure Range (p.s.i.g.) 302-84 348-97 303-155 323-146 195-150 Yields(On CFCharged), Wt. percent:

0 (11o-165 FJ-. 114 122 89 106 47 C7 (16s-194 F.) s 6 5 9 2 j o@(iai-266 FJ.- 49 46 49 56 34 o 34 32 63 55 6 Total Alkylate(Depentanized).- 20'5v 206 '206' 226 89 Ethylene-converted 10oV '10o 9s10o 58 MS Analysis, Ce Cut (Mol Percent) :2

2,3-Dimethy1butane 89.2, 91.0 91.0 S-Methylpentane 4.0 3. 0 4. 72,2-Dimethy1butane-- 0. 2 1. 0 2. 8 nexane 0.0 0.2 0.4 2-Methy1pentane-6. 6 4. 8 1. 1

i Catalyst for this test prtpared by complexing BF; with ester prlor torun. No excess BFa added. Catalyst contained 37.8 wt. percent B a.

2 Mass spectrometer.

butane was' added and then BB3 (90 grams) was pressured in. The chargedbombs Were placed in a rocker and allowed to rock for 20 hours. At theend of this time the` liquid catalyst layer was withdrawn from the bomb.The

diisobutylene` was added, the reaction mixture was stirred for minutes,separated, washed and then distilled on a 15-plate Oldershaw column.

hydrocarbon was then water washed to remove dissolved 5 Results of thistest are shown in Table III." BF3 and ester. A sample was submitted forPodbielniak e Y distiiiation. A C cut from the podbieiniak distillationTable III was analyzed by mass spectrometer. In some cases afterTolueue/Dsobutyleue (molar) 2 sampling, the remaining maior portion ofthe product was percent toluene reacting 81.4 debutanized on anOldershaw column and then fraction- 10 percent outyl toluene (molar) 163.1 ated on a pacleed column. I lsomer distribution: y

The results in Table I show that excellent yields were m t Butyl toluene13 obtained with all the esters when free-EP3 was present. p t Butyltolueue 87 Run No. 5, which was carried out with a preformed com-Percent purity of Butyl tolueue out 10o plex of ethylldihydrogenorthophosphate and BF3, using 15 Wt. percent material boiling above: lno free-BF3 in the reactor, had a very markedly lower eutyl toluene(based on total hydrocarbon yield and low conversion of ethylene.charge) 25 4 The physical characteristics of these esters are set out lO h in Table IL i1 toluene c urged. Y

Table II The high para to meta-t-butyl toluene ratio is of greatinterest. G u Deoim- In Table IV there are set out results in thetesting of (S222, Cf) "D prllltf various alkyl acid p yrophosphates bymeans of batch O. operation under conditions described for Tests l-4.

The results in Table IV show that over 200% of de- Ethyl flililyhdrggenOighlipholphaemggg lg gg pentanized alkylate product is obtained by thecatalyst 8i iigtcilgi iiydslogrgiertiriopiiiisgiite-.. 1.333 1. 421iso-165 Pall' 0f the mvellflon In RUB .9 all the ethylene Was COH-Dusooctyl hydrogen Orthophosphate 1.020 1. 443 215-220 verted; 90% beingconverted in the other runs. The C,

cut contained over 90% of diisopropyl.

Table IV Run No 7 u A 8 9 Ester DIISOamyl Diethyl Dilsoocty1 HydrogenHydrogen Hydrogen Pyrophosphate Pyropliosphate Pyrophosphate Conditions:

Isobutane/Olefn (Molar) 3.1 3.1 I 2.8 Hydrocarbon/Ester (Weight) 21.021.0 11.3 Bin/Ethylene (Weight) 0.3 0.3 0.8 Time (Hours) 20 20 20Temperature 0.)..- 20-30 20-30 20-25 Pressure Range (.ps.i. 260-140236-85 301-119 Wt. v Wt. y Wt. Percent Br.No. Percent Br.No. Percent Br.No.

C Oh d malga?? Y me) 27 25 15 o, (11o-165 F.) 96 o. o e9 o. o 104 o. oo1 (16s-194 F.)--- 8 0.1 s 0.0 13 0.o ot (isi-266 F.) 54 0.0 39 0.2 533.9 et+ Y 2s 53 Total Alkylate (Depentanized) 213 144 223 EthyleneConverted 90 89 100 MS Analysis, Ct Cut (Mol Percent) l:

2, 3-Dimethylbutane- 91.3 91.8 3Metliy1pentaue 4. 7 4, 0 2,2Dimethylbutane- 2. 6 3, 4 2-Methylpentane 1. 4 0. 2 n=Hexane 0.0 0.6

1 Mass spectrometer.

Run No. 6 65 The-physical properties of the three esters used are Y lset out in Table V. Depolyalkylation of toluene- A stirred glassreactlon Table V flask fitted with condenser, dropping funnel and therfmometer was used for this test. The catalyst was pre- Decompared bysaturating ethyl dihydrogen orthophosphate with S225 ((ri ne" plgsiitttmBF3. The finished catalyst contained 37.8% BF3. The' 00a catalyst (280ml.) and 644 g. of nitration grade toluene were charged to the reactionvessel. A total of 403 g. of glethyllsregen liylgoiilwlphfillet.; 1.527 1. 437 141-145 technical grade diisobutylene was then slowly addedto the Dggigi Hgtitrgggg Pgrrghgssghtl: i: 1193 ij igreatiou vessel overa period of 55 minutes. The pot 75 www Run No. I

flriethyl phosphate was used as the ester in a run carried out under theprocedure of runs 1-4. This pair produced a yield of alkylateindistinguishable from operation with BF3 alone, i.e., this ester is nota promoter. The conditions and yields are set out below.

Isobutane/ethylene (molar) 3.2 BFS/ethylene (Weight) 0.8Hydrocarbon/ester (weight) 11.3 Temperature, C. 30-35 Pressure, p.s.i.g310-275 Yields (on ethylene charged):

Isopentane 3 Ce-i- 33 Alkylate (depentanized) 33 Thus having describedthe invention, what is claimed is:

1. An alkylation process comprising contacting (a) an alkylatable feedhydrocarbon from the class consisting of (l) isoparaflin having from 4to 8 carbon atoms and (2) aromatic hydrocarbon and (b) an olefin havingfrom 2 to 12 carbon atoms, in the presence of a catalyst comprisingessentially (i) an alkyl hydrogen phosphate ester having at least onehydrogen atom and at least one alkyl group containing from 1 to 13carbon atoms, and (ii) EP3, said BF3 being present in an amount inexcess of about 1 mole per mole of said ester, at a temperature betweenabout 30 C. and a temperature substantially below the temperature atwhich said ester decomposes, and at a pressure suicient to maintain asubstantial portion of said reactants in the liquid state, andseparating a hydrocarbon product mixture containing alkylate product ofsaid feed hydrocarbon and said olen.

2. An alkylation process wherein an isoparain having from 4 to 8 carbonatoms and an olen having from 2 to 12 carbon atoms are contacted, in amolar ratio of isoparafin to olefin between about 2 and 50, at atemperature between about 20 C. and 125 C. and a pressure between aboutand 2000 p.s.i., said pressure being at least sutlicient to keep asubstantial portion of said reaotants in the liquid state, for a timesuicient to permit an appreciable amount of alkylation reaction to takeplace, in the presence of a catalyst comprising essentially (i) an alkylhydrogen phosphate ester having at least one hydrogen atom and at leastone alkyl group containing from 1 to 13 carbon atoms, and (ii) borontriuoride, said BF3 being present in an amount in excess of one mole permole of said ester present, removing a product hydrocarbon mixture fromsaid contacting zone and an alkylate hydrocarbon product is separatedfrom said mixture.

3. The process of claim 2 wherein the BF3 is present in an amount, inexcess of 1 mole per mole of ester, such that the free-EP3 to olenweight ratio is between about 0.2-and 1.5. v

4. The process of claim 2 wherein said isoparaiin is isobutane.

5. The process of claim 2 wherein said isoparain is diisopropyl.

6. The process of claim 2 wherein said olefin is ethylene.

7. The process of claim 2 wherein said olein is propylene tetramer.

8. -T he process of claim 2 wherein said ester is diethyl hydrogenorthophosphate.

9. The process of claim 2 wherein said ester is diisooctyl hydrogenorthophospate. l

10. The process of claim 2 wherein said ester is diethyl hydrogenpyrophosphate.

11. The process of claim 2 wherein said ester is diisooctyl hydrogenpyrophosphate.

No references cited.

1. AN ALKYLATION PROCESS COMPRISING CONTACTING (A) AN ALKYLATABLE FEEDHYDROCARBON FROM THE CLASS CONSISTING OF (1) ISOPARAFFIN HAVING FROM 4TO 8 CARBON ATOMS AND (2) AROMATIC HYDROCARBON AND (B) AN OLEFIN HAVINGFROM 2 TO 12 CARBON ATOMS, IN THE PRESENCE OF A CATALYST COMPRISINGESSENTIALLY (I) AN ALKYL HYDROGEN PHOSPHATE ESTER HAVING AT LEAST ONEHYDRGEN ATOM AND AT LEAST ONE ALKYL GROUP CONTAINING FROM 1 TO 13 CARBONATOMS, AND (II) BF3, AND BF3 BEING PRESENT IN AN AMOUNT IN EXCESS OFABOUT 1 MOLE PER MOLE OF SAID ESTER, AT A TEMPERATURE BETWEEN ABOUT-30*C. AND A TEMPERATURE SUBSTANTIALLY BELOW THE TEMPERATURE OF WHICHSAID ESTER DECOMPOSES, AND AT A PRESSURE SUFFICIENT TO MAINTAIN ASUBSTANTIAL PORTION OF SAID REACTANTS IN THE LIQUID STATE, ANDSEPARATING A HYDROCARBON PRODUCT MIXTURE CONTAINING ALKYLATE PRODUCT OFSAID FEED HYDROCARBON AND SAID OLEFIN.